生活中(in life) is a word, 却（But,however) is another word.

第一次看到你的书是在学校的图书馆。在网上看到你的书很火，但现实生活中却没多大的留意。------------- The Chinese was not good. Maybe there were some typos by you or by the original writer. It was grammatically incorrect: 留意 is a verb， and unlikely to be used that way. Anyway, let me give a translation: The first time I saw your book was in the library of our school. I noticed on the internet that your books are very popular, while you're so unobtrusive in real life. 生活中/却 in real life/ otherwise

1）"看到“ == saw. "到” here is a "补语" that indicates a complete action. e.g. "收到“， ”见到“ ， "达到". 2) the phrase is "现实生活中" == in real life. Followed by "却” == yet,however, but. Seems a bit redundant, seeing that there's already a "但”。 It's supposed to be a "副词“ but I am not sure if in this sentence it is functioning as a "连词”，similar to "而“. Maybe a Chinese grammar expert can tell us.

但现实生活中 却 没多大的留意 中=in 却=however, but 这句话是说: however, in the real life, I did not notice it.